Web AppBuilder for ArcGIS won't move to the ArcGIS API for JavaScript v4.x API for 2D capabilities until it's functionally equivalent to the v3.x API.

The ArcGIS API for JavaScript v4.x API is planned to be "complete" (e.g., fully support 2D functionality) by the end of 2017/early 2018. Once that happens, Web AppBuilder will probably migrate approx 4-6 months later. Please note these are all rough time estimates and may change.

Web AppBuilder for ArcGIS won't move to the ArcGIS API for JavaScript v4.x API for 2D capabilities until it's functionally equivalent to the v3.x API.

The ArcGIS API for JavaScript v4.x API is planned to be "complete" (e.g., fully support 2D functionality) by the end of 2017/early 2018. Once that happens, Web AppBuilder will probably migrate approx 4-6 months later. Please note these are all rough time estimates and may change.

It should be helpfull to have an ArcGIS API for JavaScript v4.x API functionnality roadmap. Some of those functionnaities due to the end of thhis year, are not relevant for the WAB. According to this roadmap it's probably possible to start a beta version of the WAB with 4;x support for 2D apps, for the end of the year.

We appreciate your suggestion, however the level of effort to enable this functionality (e.g., enabling support for the JS APIs v3.x and v4.x and associated beta APIs) would detract Dev resources for working on core Web AppBuilder.